Справочник Пользователя для AeroComm Corporation 4424200
3/23/2006
8
3. Specifications
3.1 I
NTERFACE
S
IGNAL
D
EFINITIONS
The LT4424 has a simple interface that allows OEM Host communications with the transceiver. Table 1
– Pin Definitions, shows the connector pin numbers and associated functions. The I/O direction is with
regard to the transceiver. All I/O is 5VDC TTL level signals except for RSSI. All inputs are weakly pulled
High and may be left floating during normal operation.
– Pin Definitions, shows the connector pin numbers and associated functions. The I/O direction is with
regard to the transceiver. All I/O is 5VDC TTL level signals except for RSSI. All inputs are weakly pulled
High and may be left floating during normal operation.
Table 1 – Pin Definitions
Pin
Type
Signal Name
Function
1
NC No
Connect
2
O
TXD
Transmitted data out of the transceiver
3
I
RXD
Data input to the transceiver
4
NC No
Connect
5 GND
GND Signal
Ground
6
O
Hop Frame
HOP FRAME – Active Low when the transceiver is hopping.
7
O
CTS
Clear to Send – Active Low when the transceiver is ready to accept data for transmission.
8
I
RTS
Request to Send – When enabled in EEPROM, active Low when the OEM Host is ready to
accept data from the transceiver. NOTE: Keeping RTS High for too long can cause data loss.
accept data from the transceiver. NOTE: Keeping RTS High for too long can cause data loss.
9
NC No
Connect
10
PWR
VCC
5V ± 2%, ± 50mV ripple
11
PWR
VCC
5V ± 2%, ±50 mV ripple
12 I/O 9600_BAUD/
Packet Frame
9600_BAUD – When pulled logic Low before applying power or resetting the transceiver’s
serial interface is forced to a 9600, 8, N, 1 rate. To exit, transceiver must be reset or power-
cycled with 9600_Baud logic High.
*Note: 9600_BAUD should only be used to recover the radio from an unknown baud rate and
should not be used during normal operation.
Packet Frame – When programmed in EEPROM, Packet Frame will transition logic Low at the
start of a received RF packet and transition logic High at the completion of the packet.
serial interface is forced to a 9600, 8, N, 1 rate. To exit, transceiver must be reset or power-
cycled with 9600_Baud logic High.
*Note: 9600_BAUD should only be used to recover the radio from an unknown baud rate and
should not be used during normal operation.
Packet Frame – When programmed in EEPROM, Packet Frame will transition logic Low at the
start of a received RF packet and transition logic High at the completion of the packet.
13
O
RSSI
Received Signal Strength Indicator - An analog output giving a relative indication of received
signal strength while in Receive Mode.
signal strength while in Receive Mode.
14
I
WR_ENA
EEPROM Write Enable – When pulled logic Low, it allows the Host to write the on-board
EEPROM. Resetting the transceiver with this pin pulled Low may corrupt EEPROM data.
EEPROM. Resetting the transceiver with this pin pulled Low may corrupt EEPROM data.
15
I
UP_RESET
RESET – Controlled by the LT4424 for power-on reset if left unconnected. After a Stable power-
on (250ms) a 50us logic High pulse will reset the LT4424. Do not power up the transceiver
with this pin tied Low.
on (250ms) a 50us logic High pulse will reset the LT4424. Do not power up the transceiver
with this pin tied Low.
16 GND
GND Signal
Ground
17
I
Command/Data
When logic Low, transceiver interprets Host data as command data. When logic High,
transceiver interprets Host data as transmit data.
transceiver interprets Host data as transmit data.
18
NC No
Connect
19
NC No
Connect
20
O
IN_RANGE
In Range – Active Low when a Client radio is in range of a Server on same Channel with the same
System ID.
System ID.
I = Input to the transceiver
O = Output from the transceiver